Area Forecast Discussion
Issued by NWS Quad Cities, IA IL

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FXUS63 KDVN 222015

Area Forecast Discussion
National Weather Service Quad Cities IA IL
315 PM CDT Sun Oct 22 2017

Issued at 300 PM CDT Sun Oct 22 2017

Much cooler today in the 50s behind departing sfc low now over the
Chicago area. There was a brief period of 30 mph wind gusts on the
backside of the low in a relatively narrow isallobaric
max/pressure rise immediately west of the low-level trough. These
higher gusts are now confined to the far eastern CWA, over parts
of Bureau and Putnam Counties. There were also light rain showers
across the CWA, but most areas will not receive more than a trace
or a few hundredths through the remainder of the afternoon.


.SHORT TERM...(This Evening through Monday)
ISSUED AT 300 PM CDT Sun Oct 22 2017

This Evening and Tonight

850mb trough axis and attendant frontogenesis will provide enough
convergence and lift to result in periods of light rain lingering
over the far east into tonight. Before this elevated thermal
gradient slides into eastern Illinois, the best chances for
measurable rain of less than a tenth of an inch are over Bureau
and Putnam Counties. Otherwise, clear skies and light winds allow
overnight lows to reach the lower 40s on avg. Fog is possible in
low-lying and river valley locations, but kept as patchy in grids
for now due to low confidence on spatial extent and severity.


Will likely have scattered light rain showers developing during
the late morning through the afternoon as 700mb trough axis and
associated convergence and mid-level DCVA provide moderate
forcing for ascent. However, low-level moisture is limited. For
that reason, kept PoPs at 20% because chances for measurable rain
at any one location are low. For temps, expect highs in the upper
50s to lower 60s. Uttech

.LONG TERM...(Monday Night through Sunday)
ISSUED AT 300 PM CDT Sun Oct 22 2017

Chilly conditions will last through the extended, with a growing
possibility that the growing season will officially end in a hard
freeze as we approach the end of the week.

To begin the period, the upper low over the Great Lakes will see
energy join in the trof, resulting in a near fujiwhara rotation of
energy centers. This could bring an unpleasant combination of
light rain and cool temperatures, and is nearly certain to bring
plenty of clouds and cool temperatures to the CWA. Rainfall is
most likely in the northeast Monday night and Tuesday, while the
southwest is most likely to remain dry. The clouds will help keep
any frost at bay, though this period will definitely result in the
widespread use of heating in the area. In any case, this period
of weather will set the stage for even cooler weather towards next

A warm up back to the 50s and 60s is expected Wednesday and
Thursday, while the upper pattern flattens out ahead of strong cold
front due Friday. Cold windy weather is expected from Thursday night
through Friday afternoon, as a cold canadian high builds in. There
are some low pops lingering in this period for rain and snow, but
this will likely be dry period now that models have abandoned the
synoptic low solution previously supported by the 00Z ECMWF.  Highs
this upcoming weekend may be limited to the lower to mid 40s, with
lows in the mid 20s to lower 30s.


.AVIATION...(For the 18Z TAFS through 18Z Monday Afternoon)
ISSUED AT 1238 PM CDT Sun Oct 22 2017

VFR conditions to prevail through the next 24 hrs. Low clouds
around 4000 ft AGL at KMLI/KBRL will improve through the early
afternoon. Also expect wind speeds to decrease through the mid to
late afternoon. Did not include fog in TAFs at this time. However,
later shifts may need to reassess potential for late tonight into
early Monday morning. Uttech




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